Method and means for burning gases



1,592,616 H. F. NOYES ET AL Filed April 4. 1925 z Sfiets-"Sfi'et 1 Harr F 1V a m I u July 13 1926.

METHOD AND MEANS FOR BURNING GASES July 13, 1926. 1,592,616

H. F. NOYES ET AL METHOD AND MEANS FOR BURNING GASES Filed April 4. 1925 2 Sheets-Sheet 2 J5 l W 1' 15 m 0 @1 if; 35

Th m V r 1 I5 X. I 2! 5 i i I i Z. nil 1: I 1 65 i I W M W. Ad/ iwm@ 15 19 35 flarry FNoyea,

zzoz/wmzz ez,

Patented July 13, 1926.

UNITED STATES 1,592,616 PATENT OFFICE.

HARRY F. NOYES AND ROTHE WEIGEL, OF CHICAGO HEIGHTS, ILLINOIS, ASSIGNORS TO VICTOR CHEMICAL WORKS, OF CHICAGO HEIGHTS, ILLINOIS, A CORPORATION or ILLINOIS.

METHOD AND MEANS FOR BURNING GASES.

Application filed April 4, 1925. Serial No. 20,745.

This invention relates to a new and improved method of, and means for burning the gases which are evolved from ablast furnace or the like, and more particularly, from a furnace of this character in which phosphorus, phosphoric acid and various other compounds are volatilized from mixtures of phosphatio material, silica and coke.

The gases evolved from a blast furnace employed for this purpose contain a mixture of carbon monoxide, carbon dioxide, phosphorus, oxides of phosphorus, and various other volatilized products, and it is desired to oxidize completely the combustible ingredients of said gases for the purpose not only of recovering the heat units of said combustion but in order to obtain compounds of phosphorus and subsequently recover them in some; well-known manner. The heat generated by the combustion of these gases and volatilized products may either be used for steam generation in boilers or for heating the checker-work of hot blast stoves which in turn are used to preheat the air which is used in the blast furnace.

The usualtype of stoves or boilers used in conjunction with blast furnaces provides for a combustion chamber, which is part of said unit. Since each combustion chamber must have its individual burner, it is necessary to employ long gas mains of relatively small diameter to lead the gases to these individual burners. Not only does this make it necessary to provide complicated gas mains and connections but also necessitates the burning of the gases at several different points. Moreover, a stove or boiler must contain sufficient volume to enclose the combustion chamber and heating surface sufficiently large to absorb the heat generated in said combustion chamber.

A system of this kind presents certain serious objections in the manufacture of phosphoric acid and phosphorus compounds since the gases contain volatilized products which condense or build up in the gas mains of relatively small diameter and eventually clog these passages to the point of serious resistance to the gases and draft, necessitating the cleaning of these mains, lines and burners, which is both time consuming and wasteful of the volatilized products which it is desired to recover. Moreover, it has been found that the gases evolved from a furnace manufacturing phosphorus compounds have certain characteristics which makes it diflicult to burn them in chambers where the temperature is relatively low. In the ordinary system, therefore, where the stoves are continually being changed from gas to air, the temperature of the combustion chamber is lowered when the stove is first put on gas and considerable time is consumed .in raising the temperature to a point where these gases are efiicientlv burned.

It is an object of the present invention to provide a means and method for the combustion of the gaseous products of a blast furnace or the like, and particularly, such a furnace when used for the production of phosphorus and phosphorus compounds.

It is an additional object to provide a means and method of this character in which a high recovery is bad of the desired products together with a high recovery of the heat developed by the reactions. It is a further object to provide a means and method in which the combustion of the gaseous products is maintained at a substantially uniform and high temperature, such temperature being preferably such as to accumulate the material eliminated from the gases in the form of a liquid or semi-fused mass.

Other and further objects will appear as the description proceeds.

We have illustrated in the accompanying drawings somewhat diagrammatically a preferred form of apparatus adapted for carrying out our improved method In the drawings- Figure l is a fragmentary plan view partly in section showing the installation;

Figure 2 is an elevation partly in section taken on lines 22 of Figure 1, and

Figure 3 is a view similar to Figure 2, but taken on line 3 -3 of Figure 1.

In the drawings, we have shown at 11 a usual type of blast furnace, which is used for the production of phosphorus or phosphorus compounds volatilized from mixtures of phosphatic material incombination with silica and coke. The blast furnace 11 may be provided with any usual type of charging bell 12 and with a bustle pipe 13 having connection with tuyeres 14. The downcomer 15 of the furnace leads to the dust-catcher, 16

' and the gases are lead from the dust-catcher through pipe 17 to the burners 18. These burners 18 are directed into a flame chamber 19 which forms a part of the elongated combustion chamber 20.

A baflle wall 21 is preferably located in front of the burners 18. The flame impinges on this wall and this facilitates the fusion and deposition of the impurities, fume or solid material suspended in the gases. The combustion chamber20 is provided with. a plurality of baflie walls 22, which are adapted. to cause the flame and products of combustion to take a tortuous passage, thus further facilitating the deposition and fusion of the material carried by the gases.

The hot blast stoves 23 and 24 are connected to the combustion chamber 20 by the passages 25 and 26 controlled by valves 27 and 28. The hot air off-takes 29 and 30 of the stoves are connected by pipe 31 with the bustle pipe 13. The cold blast passages 32 and 33 are provided for introducing blast air. Passages 34 and 35 are provided for leading off the products of combustion to usual types of apparatus for the recovery of the phosphorus and phosphoric compounds contained in the gas. These forms of apparatus are well known in the art and need not be shown or described in detail.

The hot blast stove 23 is of a present usual type and is provided with the chamber 36 which is utilized as a combustion chamber in present practice. The products of combustion pass up this chamber 36, over the wall 37 and down through the checkerwork 38. Thehot blast stove 24 is provided with no open combustion chamber, but with two series of checker-work 38 and 39 divided by the wall 40. The gases pass up through the checker-work 38, over the wall 40 and down through checker-work 39. Consequently, the type of stove 24 is capable of greater heat recovery than the type 23, since no space is occupied by an open combustion chamber. The furnaces 41 and 42 are also shown connected with the end 43 of the combustion chamber 20. These furnaces may be any type of means for utiliz mg the waste heat of the products of combustion.

In the operation of the apparatus shown according to our method, the blast furnace will be continuously under blast and will be evolving blast gases containing among other elements phosphorus and phosphoric acid and various other phosphorus compounds. These blast gases are led through the downcomer 15 to dust-catcher 16 where the larger entrained solid material is eliminated. The gases then pass to the burners 18 and the flame from the burners projects agamst the baflle wall 21 and into the chamber 20. The products of combustion are relieved of their entrained solid material and fume in the combustion chamber, this material being deposited in a liquid or semi-fused state. The relatively clean gases are then led to the desired means for utilizing their heat;

While only two hot blast stoves have been shown, it will be understood that ordinarily a greater number will be used as in present blast furnace practice. One or more of the stoves will be connected to the combustion chamber by proper adjustment of the valves and passages and the products of combustion will pass through the stove, giving up the major portion of their heat therein. The gases are led from the stove to the phosphorus recovery apparatus, which may be of any usual type, such for example, the Cottrell precipitator which is well known in the art.

Oneor more of the stoves will be disconnected from the combustion chamber and cold blast air will be introduced to the stove. This air will be heated in the stove and led to the bustle pipe 13 and into the blast furnace through the tuyeres. Some of the products may also be led to the furnaces 41 and 42 and their heat may be utilized for the generation of steam for supplying power for the operation of blast fans, or for any other desired purposes. After the desired portion .of the heat of the gases has been absorbed in the means associated with the furnaces, the gases will be led to the phosphorus recovery means.

By our method, the combustion of the blast gases is carried on continuously at a single point, and therefore, may be maintained at a high, substantially constant temperature, such as is adapt-ed for the greatest recovery of the phosphorus content. The method and apparatus also permits the utilization of a greater area in the hot blast stoves for the storing of heat. A further desirable result is the fact that the 'fume and entrained solids are deposited in the combustion chamber and not carried into the hot and its compounds, said combustion being continuous and thereafter utilizing the specific heat of the products of combustion selectively in heat utilizing units.

2. A process for the recovery of phosphorus and its compounds which comprises the combustion of gases containing phosphorus and its compounds, said combustion being continuous, and at a relatively high and thereafter substantially constant temperature, and utilizing the specific heat of the products of combustion selectively in heat utilizing units.

' 3. A process for reducing and eliminating which consists in burning the gas continuously in combustion chambers, maintaining such combustion at a temperature suflicient to liquefy, fuse or semi-fuse the eliminated material, and thereafter using the specific heat of the products of combustion selectively in heat utilizing units.

5. Apparatus for the combustion of blast furnace gases high in phosphorus content,

the elimination of such impurities therefrom and the utilization of the heat therefrom, consisting in a combustion chamber associated With the blast furnace,-a bafile wall in said combustion chamber against which the flames impinge to facilitate the fusion and deposition of the impurities in the gases, and a plurality of heat utilizing units associated with the combustion chamber and adapted to be selectively connected thereto.

6. Apparatus for the combustion of blast furnace gases high in phosphorus content, the elimination of such impurities therefrom and the utilization of the heat therefrom, consisting in a combustion chamber associated with the blast furnace, a plurality of baffie walls in said combustion chamber adapted to give the flame and products of combustion a tortuous passage to facilitate the deposition of entrained material, and a plu rality of heat utilizing units associated with the combustion chamber and adapted. to be selectively connected thereto.

Signed at Chicago Heights, Illinois, this first day of April, 1925.

. H. F. NOYES.

ROTHE WEIGEL. 

